Pressure fryers are used to cook various food products, such as poultry, fish, potato products, and the like. Pressure fryers include one or more cooking chambers, sometimes referred to as “fryer pots”, that are filled with a cooking medium such as oil or solid fats (e.g., shortening). Each cooking chamber includes a lid that seals the chamber and a heating element that heats the cooking medium to a desired cooking temperature. The amount of time sufficient to cook the food product at a given cooking temperature may depend on the type and the amount of food product that is being cooked in the cooking chamber. When the food product is submerged in the hot cooking medium, the food product begins to cook and release steam, which pressurizes the cooking chamber. The increased pressure in the cooking chamber reduces the cooking time and helps prevent the food product from drying out, in an optimum pressure cooking cycle.
Pressure fryers typically include a valve that selectively allows the pressure within the cooking chamber to vent prior to opening the lid. The valve is closed during the cooking cycle so that pressure can build up in the cooking chamber. This build-up of pressure is caused, at least in part, by steam generated through vaporization of moisture within the food product. During cooking, a pressure regulator or control valve may be used to limit the operating pressure to an optimal level, typically about 11-12 Pounds per Square Inch (PSI). How quickly the pressure in the cooking chamber reaches the optimal operating pressure is dependent on how much moisture is in the food product and on how much food product is loaded into the pressure fryer.
Typically, large loads of food product with a high moisture level and/or a high surface area result in a cooking cycle that reaches its optimum operating pressure faster than a small load of food product having a low moisture content and/or a low surface area. For example, cooking a full 8-head load of chicken may result in a cooking cycle that reaches the optimum operating pressure for cooking chicken in four to five minutes. In contrast, cooking a 2-head load of chicken may take substantially longer to reach the optimum operating pressure. For a typical cooking cycle of between twelve and twenty minutes, pressure fryers may be designed to produce optimal results for a full load of chicken. Thus, because a smaller load may take nearly the entire cooking cycle to reach optimal operating pressure, smaller loads may require longer overall cooking times to avoid undercooking. This longer cooking time and lack of pressure may result in small loads failing to benefit from the advantages of pressure-frying.
Thus, there is a need for improved systems and methods for adjusting the pressure in pressure fryers that reduces the dependence of pressure on the properties of the food load.